1. Field of the Invention
The present invention relates to orthopedic surgery, and in particular to devices and prosthesis for stabilizing and fixing the bones and joints of the body. Particularly, the present invention relates to a multi-planar, taper lock screw for securing a spinal rod to a vertebra, wherein the screw can be easily inserted into a vertebra and connect to a spinal rod that can be connected to other vertebrae not on the same plane and can provide a structural configuration that facilitates ease of insertion or removal of the screw as desired. More particularly, the present invention relates to a novel multi-planar, taper lock screw having a proximal flange that is easily accessible to facilitate the connection of a complementarity configured gripping tool for improved ease of locking and unlocking of the screw when desired.
2. Background of the Technology
It is a common surgical requirement to stabilize and fix bones and bone fragments in a particular spatial relationship to correct the location of skeletal components due to injury or disease. This can be accomplished by using a number of bone pins, anchors, or screws placed in bones across a discontinuity in the bone or bone fragments, such as a fracture, or adjacent vertebrae, or a joint, connected by a rod to maintain a predetermined spatial location of the bones or bone fragments. In some cases the use of these devices may be permanently implanted in the subject. In other cases, the devices may be implanted only as a temporary means of stabilizing or fixing the bones or bone fragments, with subsequent removal when no longer needed. It is also common that device implants that were intended to be permanent may require subsequent procedures or revisions as the dynamics of the subject's condition warrant. For these reasons, it is desirable that an implanted device be provided, which can be easily locked and unlocked as desired by the surgeon.
Spinal fixation apparatuses are widely employed in surgical processes for correcting spinal injuries and diseases. These apparatuses commonly employ longitudinal link rods secured to the bone such as vertebrae by spinal bone fixation fasteners such as pedicle screws, hooks and others.
Many conventional devices for locking a spinal rod to a fixation hook or screw do not offer the needed variability to allow the spinal rod to be easily connected to adjacent vertebrae, which are not aligned on the same plane. Some effort has been made to provide a multi-planar screw; however, even for devices that have attempted to address the issue of securing rods to differently aligned vertebrae, there remains the problem of providing such a multi-planar screw that can also be easily locked and unlocked.
To meet the problem of securely connecting adjacent vertebrae, not on a common plane a requirement exists to provide a multi-planar, taper lock screw that can be easily inserted and easily removed from the vertebral bone as desired. It is also desirable that such a screw be configured so that it can be locked into position in relation to the bone and the spinal rod without the need to exert any additional torque to the device or force on the patient. Additionally, such a multi-planar screw that can be used without the need for an additional locking piece, such as a set screw or the need to thread a locking device into place would be desirable.
Conventional efforts to meet this need have fallen short in that no spinal screw has been provided that adapts the spinal rod to the multi-planar environment of the spine while providing a screw head configuration that presents ease of locking and unlocking the rod to the screw.
Thus a need exists for a multi-planar, taper lock screw that also provides a screw head configuration that is easily grasped by a complementary tool used by an operator for locking and unlocking the rod and screw.